Photovoltaic (PV) modules or arrays produce electricity from solar energy. Electrical power produced by PV modules reduces the amount of energy required from non-renewable resources such as fossil fuels and nuclear energy. Significant environmental benefits are also realized from solar energy production, for example, reduction in air pollution from burning fossil fuels, reduction in water and land use from power generation plants, and reduction in the storage of waste byproducts. Solar energy produces no noise, and has few moving components. Because of their reliability, PV modules also reduce the cost of residential and commercial power to consumers.
PV cells are essentially large-area semiconductor diodes. Due to the photovoltaic effect, the energy of photons is converted into electrical power within a PV cell when the PV cell is irradiated by a light source such as sunlight. PV cells are typically interconnected into solar modules that have power ranges of up to 100 watts or greater. For large PV system special PV modules are produced with typical power range of up to several 100 W. A photovoltaic module is the basic element of a photovoltaic power generation system. A PV module has many solar cells interconnected in series or parallel, according to the desired voltage and current parameters. PV cells are connected and placed between a polyvinyl plate on the bottom and a tempered glass on the top. PV cells are interconnected with thin contacts on the upper side of the semiconductor material. The typical crystalline modules power ranges from several W to up to 200 W/module.
In the case of facade or roof systems the photovoltaic system may be installed during construction, or added to the building after it is built. Roof systems are generally lower powered systems, e.g., 10 kW, to meet typical residential loads. Roof integrated photovoltaic systems may consist of different module types, such as crystalline and micro-perforated amorphous modules. A portion of natural sunlight is transferred into the building through the modules. Roof-integrated photovoltaic systems are integrated into the roof, such that the entire roof or a portion thereof is covered with photovoltaic modules, or they are added to the roof later. PV cells may be integrated with roof tiles.
PV modules/arrays require specially designed devices adapted for interconnecting the various PV modules/arrays with each other, and with electrical power distribution systems. PV connection systems are used to accommodate serial and parallel connection of PV arrays. In addition to junction boxes, a PV connection system includes connectors that allow for speedy field installation or high-speed manufacture of made-to-length cable assemblies.
Existing PV roofing tiles employ electrical connector systems that require a custom designed tool for making terminations. The tool resembles a screw driver or a wrench with end furcations that mate with slots in the connector body. When engaged in the connector body slots, the wire connection is locked or unlocked inside the connector by pivoting or rotating the tool to selectively align the slots with the open or closed position. However, in addition to the inconvenience of requiring a roof installer to carry an expensive extra tool, these furcated members tend to break in the field because of the relatively low force required to snap them off when torque is applied. Also, there is a tendency for the tool to misalign with the connector when the conductors that are inserted into the connector body are pre-tinned. Therefore there is a need for an electrical interconnection system for PV roof tiles that provides a solid, reliable electromechanical connection between the roof tile and the cable conductors.